Procedure: 1. On your wax paper, place 5-10 drops of water in one area. 3. What do you notice the water does on the wax paper?

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Ethel Cole
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1 Properties Lab NAME: Date: Background: is everywhere. It makes up about 3/4ths of the surface of the earth. It makes up 50-95% of the weight of living organisms. It is in the air we breathe, the sinks we use and in every cell of the body. has special properties that make it unusual and complex. has the ability to be a liquid, solid or gas depending on the temperature at which it is found. Each molecule of water is made up of 2 hydrogen atoms and 1 oxygen atom bonded together. is a polar molecule because the oxygen molecule has a slightly negative charge and the hydrogen has a slightly positive charge. Objectives After completing this lab you should be able to explain the importance of all of water s properties. Property Number 1 Toothpick Wax Paper Pipette 1. On your wax paper, place 5-10 drops of water in one area. 2. Move the wax paper around. 3. What do you notice the water does on the wax paper? 4. Using your toothpick, try to separate the water drop into two drops. 5. Was the water easy to separate? Explain.

Property Number 2 Materials Petri Dish Beaker of Medicine Dropper

Carefully turn the petri dish upside down. 3. Observe the results.

Describe what happened with the water and the petri dish.

Property Number 3 Materials Beaker of water Ice Cube Procedure 1.

2 Property Number 2 Materials Petri Dish Beaker of Medicine Dropper 1. Place a few drops of water on the inside of a petri dish. 2. Carefully turn the petri dish upside down. 3. Observe the results. Draw what you see below. 4. Describe what happened with the water and the petri dish. Why do you think this happened? Property Number 3 Materials Beaker of water Ice Cube Procedure 1. Place the ice cube in the water 2. Describe what happened. Why do you think this happened? 3. Explain why this property is important to aquatic organisms.

3 Property Number 4 Materials 2 Beakers Oil Salt ½ Teaspoon Stir Rod 1.There are 2 plastic cups: Cup 1: & Salt Cup 2: Oil & Salt 2. Stir each for about 20 seconds or until dissolved. 3. Record your observations below. Oil Solvent Description of Solute after 20 Seconds of Stirring 6. Summarize what you found in your experiment, based on your recorded observations. 7. Which liquid (water or oil) makes a better homogenous (same) solution?

4 Property Number 5 Data Table 1. Take a look at the data. 2. Graph the data on the chart 3. Analyze the data Oil Time Heating Cooling Heating Cooling : : : : : Legend Heating Cooling Heating Oil Color Cooling Oil :00 1:30 2:00 2:30 3:00 What do you notice about water in this lab?

5 Property Number 6 Paperclips Petri Dish 1. Fill your petri dish with water as high as you can 2. Predict the number of paper clips you will be able to float: 3. Try to float as many paper clips on top of the water How many paper clips were you actually able to float? Describe what happened: Property Number 7 Slow steady stream of water out of faucet Glass Stick Fur Procedure 1. Take the glass stick and charge it with the fur by rubbing the fur on the stick with force for 30 seconds 2. Once the glass stick is charged, place it near the steady stream of water and observe what happens. Describe what happens to the water:

6 Name: Hour: Analysis Questions: Review your data and describe why each of the following characteristics are important to human life. Property 1: is attracted to other water molecules like magnets. This attraction is due to the positive charge surrounding the hydrogen and negative charge oxygen has. The negative oxygen of one molecule is attracted to the positive hydrogen of another water molecule creating a hydrogen bond. This attraction causes cohesion. Cohesion occurs when one water molecule sticks to another. Why might this particular property be important for life? Explain using complete sentences. Property 2: not only sticks to other water molecules (cohesion) but it also sticks to substances other than water (adhesion). Why do you think this property would be important for life? Explain using complete sentences. Property 1&2 Combined: Cohesive and adhesive forces are important for the transport of water from the roots to the leaves in plants. These forces create a pull on the water column. This pull results from the tendency of water molecules being evaporated on the surface of the plant to stay connected to water molecules below them and so they are pulled along. Why do you think these properties of water combined are important to sustain life? Property 3: is one of the few substances that are less dense as a solid than as a liquid. While most substances contract when the solidify, water expands. This property is due to the hydrogen bonding between water molecules. Why is this property important for life?

7 Property 4: Because of waters high polarity, water is called the universal solvent. A solvent is a substance that dissolves, or breaks apart, another substance (known as the solute). Polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes. Since our body is mainly made up of water, why do you think having a universal solvent is important for life? Property 5: has a high heat of vaporization the energy required to convert liquid to a gas. also has a high specific heat capacity. Specific heat is a measure of heat capacity and is the heat required to raise the temperature of one game of water degree Celsius. With water having a high heat of vaporization and a high specific heat capacity, why do you think this is important for life? Property 6: molecules want to cling to each other. The cohesive forces between liquid molecules are responsible for surface tension. Surface tension allows the liquids to resist an external force. Why would surface tension be important for life? Property 7: Polarity means that the molecule has both a positively and negatively charged end. The polarity of water is responsible for effectively dissolving other polar molecules such as sugars. Why is the polarity of water important for life? 3. Draw a molecule of water. Include the charges on the oxygen and hydrogen. (Hint: See Property 1 analysis question description) a. Draw two molecules of water and label the hydrogen bond.

PreAP Properties of Water Lab

PreAP Properties of Water Lab PreAP of Water Lab Background The structure of the water molecule gives water unique properties. Water is a polar molecule, which means that it has a region with a slight negative charge (the oxygen atom),